Fallback Reshaped to MapBase when possible (same storage order and linear access to the nested expression)

Eigen/src/Core/Reshaped.h

@@ -57,34 +57,37 @@ struct traits<Reshaped<XprType, Rows, Cols, Order> > : traits<XprType>
     ColsAtCompileTime = Cols,
     MaxRowsAtCompileTime = Rows,
     MaxColsAtCompileTime = Cols,
-    XprTypeIsRowMajor = (int(traits<XprType>::Flags) & RowMajorBit) != 0,
+    XpxStorageOrder = ((int(traits<XprType>::Flags) & RowMajorBit) == RowMajorBit) ? RowMajor : ColMajor,
-    IsRowMajor = (RowsAtCompileTime == 1 && ColsAtCompileTime != 1) ? 1
+    ReshapedStorageOrder = (RowsAtCompileTime == 1 && ColsAtCompileTime != 1) ? RowMajor
-               : (ColsAtCompileTime == 1 && RowsAtCompileTime != 1) ? 0
+                         : (ColsAtCompileTime == 1 && RowsAtCompileTime != 1) ? ColMajor
-               : XprTypeIsRowMajor,
+                         : XpxStorageOrder,
-    HasSameStorageOrderAsXprType = (IsRowMajor == XprTypeIsRowMajor),
+    HasSameStorageOrderAsXprType = (ReshapedStorageOrder == XpxStorageOrder),
-    InnerSize = IsRowMajor ? int(ColsAtCompileTime) : int(RowsAtCompileTime),
+    InnerSize = (ReshapedStorageOrder==RowMajor) ? int(ColsAtCompileTime) : int(RowsAtCompileTime),
     InnerStrideAtCompileTime = HasSameStorageOrderAsXprType
                              ? int(inner_stride_at_compile_time<XprType>::ret)
-                             : int(outer_stride_at_compile_time<XprType>::ret),
+                             : Dynamic,
-    OuterStrideAtCompileTime = HasSameStorageOrderAsXprType
+    OuterStrideAtCompileTime = Dynamic,
-                             ? int(outer_stride_at_compile_time<XprType>::ret)
+
-                             : int(inner_stride_at_compile_time<XprType>::ret),
+    InOrder = Order,
+    HasDirectAccess = internal::has_direct_access<XprType>::ret
+                    && (Order==int(AutoOrderValue) || Order==int(XpxStorageOrder))
+                    && ((evaluator<XprType>::Flags&LinearAccessBit)==LinearAccessBit),
+
     MaskPacketAccessBit = (InnerSize == Dynamic || (InnerSize % packet_traits<Scalar>::size) == 0)
                        && (InnerStrideAtCompileTime == 1)
                         ? PacketAccessBit : 0,
     //MaskAlignedBit = ((OuterStrideAtCompileTime!=Dynamic) && (((OuterStrideAtCompileTime * int(sizeof(Scalar))) % 16) == 0)) ? AlignedBit : 0,
     FlagsLinearAccessBit = (RowsAtCompileTime == 1 || ColsAtCompileTime == 1) ? LinearAccessBit : 0,
     FlagsLvalueBit = is_lvalue<XprType>::value ? LvalueBit : 0,
-    FlagsRowMajorBit = IsRowMajor ? RowMajorBit : 0,
+    FlagsRowMajorBit = (ReshapedStorageOrder==RowMajor) ? RowMajorBit : 0,
-    Flags0 = traits<XprType>::Flags & ( (HereditaryBits & ~RowMajorBit) | MaskPacketAccessBit)
+    FlagsDirectAccessBit = HasDirectAccess ? DirectAccessBit : 0,
-                                    & ~DirectAccessBit,
+    Flags0 = traits<XprType>::Flags & ( (HereditaryBits & ~RowMajorBit) | MaskPacketAccessBit),
 
-    Flags = (Flags0 | FlagsLinearAccessBit | FlagsLvalueBit | FlagsRowMajorBit)
+    Flags = (Flags0 | FlagsLinearAccessBit | FlagsLvalueBit | FlagsRowMajorBit | FlagsDirectAccessBit)
   };
 };
 
-template<typename XprType, int Rows=Dynamic, int Cols=Dynamic, int Order = 0,
+template<typename XprType, int Rows, int Cols, int Order, bool HasDirectAccess> class ReshapedImpl_dense;
-         bool HasDirectAccess = internal::has_direct_access<XprType>::ret> class ReshapedImpl_dense;
 
 } // end namespace internal
 
@@ -127,9 +130,9 @@ template<typename XprType, int Rows, int Cols, int Order> class Reshaped
 // that must be specialized for direct and non-direct access...
 template<typename XprType, int Rows, int Cols, int Order>
 class ReshapedImpl<XprType, Rows, Cols, Order, Dense>
-  : public internal::ReshapedImpl_dense<XprType, Rows, Cols, Order>
+  : public internal::ReshapedImpl_dense<XprType, Rows, Cols, Order,internal::traits<Reshaped<XprType,Rows,Cols,Order> >::HasDirectAccess>
 {
-    typedef internal::ReshapedImpl_dense<XprType, Rows, Cols, Order> Impl;
+    typedef internal::ReshapedImpl_dense<XprType, Rows, Cols, Order,internal::traits<Reshaped<XprType,Rows,Cols,Order> >::HasDirectAccess> Impl;
   public:
     typedef Impl Base;
     EIGEN_INHERIT_ASSIGNMENT_OPERATORS(ReshapedImpl)
@@ -140,8 +143,9 @@ class ReshapedImpl<XprType, Rows, Cols, Order, Dense>
 
 namespace internal {
 
-/** \internal Internal implementation of dense Reshapeds in the general case. */
+/** \internal Internal implementation of dense Reshaped in the general case. */
-template<typename XprType, int Rows, int Cols, int Order, bool HasDirectAccess> class ReshapedImpl_dense
+template<typename XprType, int Rows, int Cols, int Order>
+class ReshapedImpl_dense<XprType,Rows,Cols,Order,false>
   : public internal::dense_xpr_base<Reshaped<XprType, Rows, Cols, Order> >::type
 {
     typedef Reshaped<XprType, Rows, Cols, Order> ReshapedType;
@@ -166,8 +170,7 @@ template<typename XprType, int Rows, int Cols, int Order, bool HasDirectAccess>
     /** Dynamic-size constructor
       */
     EIGEN_DEVICE_FUNC
-    inline ReshapedImpl_dense(XprType& xpr,
+    inline ReshapedImpl_dense(XprType& xpr, Index nRows, Index nCols)
-          Index nRows, Index nCols)
       : m_xpr(xpr), m_rows(nRows), m_cols(nCols)
     {}
 
@@ -199,8 +202,106 @@ template<typename XprType, int Rows, int Cols, int Order, bool HasDirectAccess>
 };
 
 
+/** \internal Internal implementation of dense Reshaped in the direct access case. */
+template<typename XprType, int Rows, int Cols, int Order>
+class ReshapedImpl_dense<XprType, Rows, Cols, Order, true>
+  : public MapBase<Reshaped<XprType, Rows, Cols, Order> >
+{
+    typedef Reshaped<XprType, Rows, Cols, Order> ReshapedType;
+    typedef typename internal::ref_selector<XprType>::non_const_type XprTypeNested;
+  public:
+
+    typedef MapBase<ReshapedType> Base;
+    EIGEN_DENSE_PUBLIC_INTERFACE(ReshapedType)
+    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(ReshapedImpl_dense)
+
+    /** Fixed-size constructor
+      */
+    EIGEN_DEVICE_FUNC
+    inline ReshapedImpl_dense(XprType& xpr)
+      : Base(xpr.data()), m_xpr(xpr)
+    {}
+
+    /** Dynamic-size constructor
+      */
+    EIGEN_DEVICE_FUNC
+    inline ReshapedImpl_dense(XprType& xpr, Index nRows, Index nCols)
+      : Base(xpr.data(), nRows, nCols),
+        m_xpr(xpr)
+    {}
+
+    EIGEN_DEVICE_FUNC
+    const typename internal::remove_all<XprTypeNested>::type& nestedExpression() const
+    {
+      return m_xpr;
+    }
+
+    EIGEN_DEVICE_FUNC
+    XprType& nestedExpression() { return m_xpr; }
+
+    /** \sa MapBase::innerStride() */
+    EIGEN_DEVICE_FUNC
+    inline Index innerStride() const
+    {
+      return m_xpr.innerStride();
+    }
+
+    /** \sa MapBase::outerStride() */
+    EIGEN_DEVICE_FUNC
+    inline Index outerStride() const
+    {
+      return ((Flags&RowMajorBit)==RowMajorBit) ? this->cols() : this->rows();
+    }
+
+  protected:
+
+    XprTypeNested m_xpr;
+};
+
+// Evaluators
+template<typename ArgType, int Rows, int Cols, int Order, bool HasDirectAccess> struct reshaped_evaluator;
+
 template<typename ArgType, int Rows, int Cols, int Order>
-struct unary_evaluator<Reshaped<ArgType, Rows, Cols, Order>, IndexBased>
+struct evaluator<Reshaped<ArgType, Rows, Cols, Order> >
+  : reshaped_evaluator<ArgType, Rows, Cols, Order, traits<Reshaped<ArgType,Rows,Cols,Order> >::HasDirectAccess>
+{
+  typedef Reshaped<ArgType, Rows, Cols, Order> XprType;
+  typedef typename XprType::Scalar Scalar;
+  // TODO: should check for smaller packet types
+  typedef typename packet_traits<Scalar>::type PacketScalar;
+
+  enum {
+    CoeffReadCost = evaluator<ArgType>::CoeffReadCost,
+    HasDirectAccess = traits<XprType>::HasDirectAccess,
+
+//     RowsAtCompileTime = traits<XprType>::RowsAtCompileTime,
+//     ColsAtCompileTime = traits<XprType>::ColsAtCompileTime,
+//     MaxRowsAtCompileTime = traits<XprType>::MaxRowsAtCompileTime,
+//     MaxColsAtCompileTime = traits<XprType>::MaxColsAtCompileTime,
+//
+//     InnerStrideAtCompileTime = traits<XprType>::HasSameStorageOrderAsXprType
+//                              ? int(inner_stride_at_compile_time<ArgType>::ret)
+//                              : Dynamic,
+//     OuterStrideAtCompileTime = Dynamic,
+
+    FlagsLinearAccessBit = (traits<XprType>::RowsAtCompileTime == 1 || traits<XprType>::ColsAtCompileTime == 1 || HasDirectAccess) ? LinearAccessBit : 0,
+    FlagsRowMajorBit = (traits<XprType>::ReshapedStorageOrder==RowMajor) ? RowMajorBit : 0,
+    FlagsDirectAccessBit =  HasDirectAccess ? DirectAccessBit : 0,
+    Flags0 = evaluator<ArgType>::Flags & (HereditaryBits & ~RowMajorBit),
+    Flags = Flags0 | FlagsLinearAccessBit | FlagsRowMajorBit | FlagsDirectAccessBit,
+
+    PacketAlignment = unpacket_traits<PacketScalar>::alignment,
+    Alignment = evaluator<ArgType>::Alignment
+  };
+  typedef reshaped_evaluator<ArgType, Rows, Cols, Order, HasDirectAccess> reshaped_evaluator_type;
+  EIGEN_DEVICE_FUNC explicit evaluator(const XprType& xpr) : reshaped_evaluator_type(xpr)
+  {
+    EIGEN_INTERNAL_CHECK_COST_VALUE(CoeffReadCost);
+  }
+};
+
+template<typename ArgType, int Rows, int Cols, int Order>
+struct reshaped_evaluator<ArgType, Rows, Cols, Order, /* HasDirectAccess */ false>
   : evaluator_base<Reshaped<ArgType, Rows, Cols, Order> >
 {
   typedef Reshaped<ArgType, Rows, Cols, Order> XprType;
@@ -213,7 +314,7 @@ struct unary_evaluator<Reshaped<ArgType, Rows, Cols, Order>, IndexBased>
     Alignment = 0
   };
 
-  EIGEN_DEVICE_FUNC explicit unary_evaluator(const XprType& xpr) : m_argImpl(xpr.nestedExpression()), m_xpr(xpr)
+  EIGEN_DEVICE_FUNC explicit reshaped_evaluator(const XprType& xpr) : m_argImpl(xpr.nestedExpression()), m_xpr(xpr)
   {
     EIGEN_INTERNAL_CHECK_COST_VALUE(CoeffReadCost);
   }
@@ -321,103 +422,21 @@ protected:
 
 };
 
+template<typename ArgType, int Rows, int Cols, int Order>
+struct reshaped_evaluator<ArgType, Rows, Cols, Order, /* HasDirectAccess */ true>
+: mapbase_evaluator<Reshaped<ArgType, Rows, Cols, Order>,
+                      typename Reshaped<ArgType, Rows, Cols, Order>::PlainObject>
+{
+  typedef Reshaped<ArgType, Rows, Cols, Order> XprType;
+  typedef typename XprType::Scalar Scalar;
 
-///** \internal Internal implementation of dense Reshapeds in the direct access case.*/
+  EIGEN_DEVICE_FUNC explicit reshaped_evaluator(const XprType& xpr)
-//template<typename XprType, int Rows, int Cols, int Order>
+    : mapbase_evaluator<XprType, typename XprType::PlainObject>(xpr)
-//class ReshapedImpl_dense<XprType,ReshapedRows,ReshapedCols, true>
+  {
-//  : public MapBase<Reshaped<XprType, Rows, Cols, Order> >
+    // TODO: for the 3.4 release, this should be turned to an internal assertion, but let's keep it as is for the beta lifetime
-//{
+    eigen_assert(((internal::UIntPtr(xpr.data()) % EIGEN_PLAIN_ENUM_MAX(1,evaluator<XprType>::Alignment)) == 0) && "data is not aligned");
-//    typedef Reshaped<XprType, Rows, Cols, Order> ReshapedType;
+  }
-//  public:
+};
-//
-//    typedef MapBase<ReshapedType> Base;
-//    EIGEN_DENSE_PUBLIC_INTERFACE(ReshapedType)
-//    EIGEN_INHERIT_ASSIGNMENT_OPERATORS(ReshapedImpl_dense)
-//
-//    /** Column or Row constructor
-//      */
-//    EIGEN_DEVICE_FUNC
-//    inline ReshapedImpl_dense(XprType& xpr, Index i)
-//      : Base(internal::const_cast_ptr(&xpr.coeffRef(
-//              (ReshapedRows==1) && (ReshapedCols==XprType::ColsAtCompileTime) ? i : 0,
-//              (ReshapedRows==XprType::RowsAtCompileTime) && (ReshapedCols==1) ? i : 0)),
-//             ReshapedRows==1 ? 1 : xpr.rows(),
-//             ReshapedCols==1 ? 1 : xpr.cols()),
-//        m_xpr(xpr)
-//    {
-//      init();
-//    }
-//
-//    /** Fixed-size constructor
-//      */
-//    EIGEN_DEVICE_FUNC
-//    inline ReshapedImpl_dense(XprType& xpr)
-//      : Base(internal::const_cast_ptr(&xpr.coeffRef(0, 0))), m_xpr(xpr)
-//    {
-//      init();
-//    }
-//
-//    /** Dynamic-size constructor
-//      */
-//    EIGEN_DEVICE_FUNC
-//    inline ReshapedImpl_dense(XprType& xpr,
-//          Index reshapeRows, Index reshapeCols)
-//      : Base(internal::const_cast_ptr(&xpr.coeffRef(0, 0)), reshapeRows, reshapeCols),
-//        m_xpr(xpr)
-//    {
-//      init();
-//    }
-//
-//    EIGEN_DEVICE_FUNC
-//    const typename internal::remove_all<typename XprType::Nested>::type& nestedExpression() const
-//    { 
-//      return m_xpr; 
-//    }
-//      
-//    EIGEN_DEVICE_FUNC
-//    /** \sa MapBase::innerStride() */
-//    inline Index innerStride() const
-//    {
-//      return internal::traits<ReshapedType>::HasSameStorageOrderAsXprType
-//             ? m_xpr.innerStride()
-//             : m_xpr.outerStride();
-//    }
-//
-//    EIGEN_DEVICE_FUNC
-//    /** \sa MapBase::outerStride() */
-//    inline Index outerStride() const
-//    {
-//      return m_outerStride;
-//    }
-//
-//  #ifndef __SUNPRO_CC
-//  // FIXME sunstudio is not friendly with the above friend...
-//  // META-FIXME there is no 'friend' keyword around here. Is this obsolete?
-//  protected:
-//  #endif
-//
-//    #ifndef EIGEN_PARSED_BY_DOXYGEN
-//    /** \internal used by allowAligned() */
-//    EIGEN_DEVICE_FUNC
-//    inline ReshapedImpl_dense(XprType& xpr, const Scalar* data, Index reshapeRows, Index reshapeCols)
-//      : Base(data, reshapeRows, reshapeCols), m_xpr(xpr)
-//    {
-//      init();
-//    }
-//    #endif
-//
-//  protected:
-//    EIGEN_DEVICE_FUNC
-//    void init()
-//    {
-//      m_outerStride = internal::traits<ReshapedType>::HasSameStorageOrderAsXprType
-//                    ? m_xpr.outerStride()
-//                    : m_xpr.innerStride();
-//    }
-//
-//    typename XprType::Nested m_xpr;
-//    Index m_outerStride;
-//};
 
 } // end namespace internal
 

Eigen/src/Core/util/IntegralConstant.h

@@ -265,6 +265,11 @@ static const auto fix(int val);
 
 #endif // EIGEN_PARSED_BY_DOXYGEN
 
+const int AutoOrderValue = 2;
+const internal::FixedInt<ColMajor>        ColOrder;
+const internal::FixedInt<RowMajor>        RowOrder;
+const internal::FixedInt<AutoOrderValue>  AutoOrder;
+
 } // end namespace Eigen
 
 #endif // EIGEN_INTEGRAL_CONSTANT_H

test/reshape.cpp

@@ -48,6 +48,18 @@ void reshape_all_size(MatType m)
     ),
     MapMat(m.data(), 4,  4)
   );
+
+  VERIFY_IS_EQUAL(m.reshaped( 1, 16).data(), m.data());
+  VERIFY_IS_EQUAL(m.reshaped( 1, 16).innerStride(), 1);
+
+  VERIFY_IS_EQUAL(m.reshaped( 2, 8).data(), m.data());
+  VERIFY_IS_EQUAL(m.reshaped( 2, 8).innerStride(), 1);
+  VERIFY_IS_EQUAL(m.reshaped( 2, 8).outerStride(), 2);
+
+  m.reshaped(2,8,ColOrder);
+
+  MatrixXi m28r = m.reshaped(2,8,RowOrder);
+  std::cout << m28r << "\n";
 }
 
 void test_reshape()